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1.
The reactions of ruthenium(II) complexes, [RuHCl(CO)(PPh3)2(B)] [B = PPh3, pyridine (py) or piperidine (pip)], with bidentate Schiff base ligands derived by condensing salicylaldehyde with aniline, o-, m- or p-toluidine have been carried out. The products were characterised by analytical, i.r., electronic, 1H-n.m.r. and 31P-n.m.r. spectral studies and are formulated as [RuCl(CO)(L)(PPh3)(B)] (L = Schiff base anion; B = PPh3, py or pip). An octahedral structure has been tentatively proposed for the new complexes. The Schiff bases and the new complexes were tested in vitro to evaluate their activity against the fungus Aspergillus flavus.  相似文献   

2.
Binuclear ruthenium(III) complexes containing a binucleating Schiff base ligand, L and Ph3P or Ph3As, [RuX2(EPh3)2]2L (X = Cl or Br; E = P or As) have been prepared by reacting [RuCl3(PPh3)3], [RuCl3(AsPh3)3], [RuBr3(AsPh3)3] and [RuBr3(PPh3)2(MeOH)] with Schiff bases in a 2:1 molar ratio. The Schiff bases used in this study were prepared by condensing the appropriate diamine with salicylaldehyde or benzoylacetone in a 1:2 molar ratio respectively. The complexes were characterised by analytical, spectral (i.r., electronic, e.p.r.) and electrochemical data. An octahedral structure has been proposed for all the new ligand-bridged binuclear RuIII complexes. The new complexes have been used as catalysts in aryl–aryl couplings and also subjected to antifungal activity studies.  相似文献   

3.
Alcohols are oxidized by N‐methylmorpholine‐N‐oxide (NMO), ButOOH and H2O2 to the corresponding aldehydes or ketones in the presence of catalyst, [RuH(CO)(PPh3)2(SRaaiNR′)]PF6 ( 2 ) and [RuCl(CO)(PPh3)(SκRaaiNR′)]PF6 ( 3 ) (SRaaiNR′ ( 1 ) = 1‐alkyl‐2‐{(o‐thioalkyl)phenylazo}imidazole, a bidentate N(imidazolyl) (N), N(azo) (N′) chelator and SκRaaiNR′ is a tridentate N(imidazolyl) (N), N(azo) (N′), Sκ‐R is tridentate chelator; R and R′ are Me and Et). The single‐crystal X‐ray structures of [RuH(CO)(PPh3)2(SMeaaiNMe)]PF6 ( 2a ) (SMeaaiNMe = 1‐methyl‐2‐{(o‐thioethyl)phenylazo}imidazole) and [RuH(CO)(PPh3)2(SEtaaiNEt)]PF6 ( 2b ) (SEtaaiNEt = 1‐ethyl‐2‐{(o‐thioethyl)phenylazo}imidazole) show bidentate N,N′ chelation, while in [RuCl(CO)(PPh3)(SκEtaaiNEt)]PF6 ( 3b ) the ligand SκEtaaiNEt serves as tridentate N,N′,S chelator. The cyclic voltammogram shows RuIII/RuII (~1.1 V) and RuIV/RuIII (~1.7 V) couples of the complexes 2 while RuIII/RuII (1.26 V) couple is observed only in 3 along with azo reductions in the potential window +2.0 to ?2.0 V. DFT computation has been used to explain the spectra and redox properties of the complexes. In the oxidation reaction NMO acts as best oxidant and [RuCl(CO)(PPh3)(SκRaaiNR′)](PF6) ( 3 ) is the best catalyst. The formation of high‐valent RuIV=O species as a catalytic intermediate is proposed for the oxidation process. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

4.
Reactions of ruthenium(II) carbonyl complexes of the type [RuHCl(CO)(PPh3)2(B)] [B?=?PPh3, pyridine (py), piperidine (pip) or morpholine (mor)] with bidentate Schiff base ligands derived from the condensation of 2-hydroxy-1-naphthaldehyde with aniline, o-, m- or p-toluidine in a 1?:?1 mol ratio in benzene resulted in the formation of complexes formulated as [RuCl(CO)(L)(PPh3)(B)] [L?=?bidentate Schiff base anion, B?=?PPh3, py, pip, mor]. The complexes were characterized by analyses, IR, electronic and 1H NMR spectroscopy, and cyclic voltammetric studies. In all cases, the Schiff bases replace one molecule of phosphine and a hydride ion from the starting complexes, indicating that Ru–N bonds in the complexes containing heterocyclic nitrogenous bases are stronger than the Ru–P bond to PPh3. Octahedral geometry is proposed for the complexes.  相似文献   

5.
Abstract

The triply halide-bridged binuclear complexes [Ru2Cl5(CO)(AsPh3)3] (AsPh3 = triphenylarsine), [Ru2Cl5(CO)(PPh3)2(AsPh3)] (PPh3 = triphenylphosphine), [Ru2Cl5(CO)(AsPh3)2(PPh3)], [Ru2 Br5(CO)(PPh3)3], [Ru2Cl5(CO)(P{p-tol}3)2(PPh3)] (P{p-tol}3 = tri-p-tolylphosphine) and [Ru2 Br2Cl3(PPh3)2(AsPh3)] were prepared from the precursor compounds ttt-[RuX2(CO)2(P)2] (X = Cl or Br) and [RuY3(P')2S]·S (Y = Cl or Br; P=PPh3, AsPh3 or P{p- tol}3 and P' = AsPh3 or PPh3; S=DMA or MeOH, where DMA = N,N'-dimethylacetamide). The molecular structures of the binuclear complexes [Ru2Cl5(CO)(AsPh3)3] (P21/c), [Ru2Br5(CO)(PPh3)3] (P21/c) and ttt-[RuCl2(CO)2(PPh3)2] (P1) were determined by X-ray diffraction methods. The complexes are always formed by two Ru atoms bridged through three halide anions, two of which are × type (from the RuII precursor) and the other is Y type (from the rutheniumIII precursor) confirming our previously suggested mechanism for obtaining this class of complexes. The RuII atom is also coordinated to a carbon monoxide molecule and two P ligands from the ttt-starting isomer whereas the RuIII atom is bonded to two non-bridging Y halides and one P' molecule. The presence of RuIII was confirmed by EPR data, a technique that was also useful to suggest the symmetry of the complexes. The absence of intervalence charge-transfer transitions (IT) in the near infrared spectrum confirms that the binuclear complexes have localized valence. The IR spectra of the complexes show; (CO) bands close to 1970 cm?1 and ν(Ru-Cl) or(Ru-Br) bands at about 230–380 cm?1 corresponding to halides at terminal or bridged positions. Two widely separated redox processes, RuII/RuII←RuII/RuIII→RuIII/RuIII, were observed by cyclic voltammetry and differential pulse voltammetry.  相似文献   

6.
The new [Ru11(PPh3)2L2] complexes [L=monoanion of tropolone, benzoylacetone, or 3-hydroxy-2-pyridinone (hypy)], [RuH(PPh3)3L′][HL′=maltol, dibenzoylmethane or 1,2-dimethyl-3-hydroxy-4-pyridinone (Hdmhypy)] and [RuIIIX2(EPh3)2L″] complexes (X=Cl, Br; E=As or P; L″=hypy, dmhypy) have been prepared, and characterized by spectroscopic techniques. Their redox behaviour was studied by cyclic voltammetry. Most of the complexes were found to be effective catalysts for the oxidation ofp-methoxybenzyl alcohol to the corresponding aldehyde in the presence ofN-methylmorpholine-N-oxide as co-oxidant.  相似文献   

7.
The products obtained by reacting ruthenium (II) complexes [RuHCl(CO)(PPh3)2(B)] [B = PPh3, pyridine (py) or piperidine (pip)] with tridentate Schiff base ligands derived by condensing salicylaldehyde or o-vanillin with o-aminophenol and o-aminothiophenol, have been characterised by analytical, i.r., electronic, 1H-n.m.r. and 31P-n.m.r. spectral studies and formulated as [Ru(L)(CO)(PPh3)(B)] (L = bifunctional tridentate Schiff base anion, B = PPh3, py or pip). An octahedral structure has been tentatively proposed for the new complexes. Some have been tested for the in vitro growth inhibitory activity against bacteria Escherichia coli, Bacillus sp. and Pseudomonas sp.  相似文献   

8.
《Polyhedron》1999,18(21):2729-2736
A family of three mixed-ligand osmium complexes of type [Os(PPh3)2(N-N)Br2], where N-N=2,2′-bipyridine (bpy), 4,4′-dimethyl-2,2′-bipyridine (Me2bpy) and 1,10-phenanthroline (phen), have been synthesized and characterized. The complexes are diamagnetic (low-spin d6, S=0) and in dichloromethane solution they show intense MLCT transitions in the visible region. The two bromide ligands have been replaced from the coordination sphere of [Os(PPh3)2(phen)Br2] under mild conditions by a series of anionic ligands L (where L=quinolin-8-olate (q), picolinate (pic), oxalate (Hox) and 1-nitroso-2-naphtholate (nn)) to afford complexes of type [Os(PPh3)2(phen)(L)]+, which have been isolated and characterized as the perchlorate salt. The structure of the [Os(PPh3)2(phen)(pic)]ClO4 complex has been determined by X-ray crystallography. The PPh3 ligands occupy trans positions and the picolinate anion is coordinated to osmium as a bidentate N,O-donor forming a five-membered chelate ring. The [Os(PPh3)2(phen)(L)]+ complexes are diamagnetic and show multiple MLCT transitions in the visible region. The [Os(PPh3)2(N-N)Br2] complexes show an osmium(II)–osmium(III) oxidation (−0.02 to 0.12 V vs. SCE) followed by an osmium(III)–osmium(IV) oxidation (1.31 to 1.43 V vs. SCE). The [Os(PPh3)2(phen)(L)]+ complexes display the osmium (II)–osmium (III) oxidation (0.26 to 0.84 V vs. SCE) and one reduction of phen (−1.50 to −1.79 V vs. SCE). The osmium (III)–osmium (IV) oxidation has been observed only for the L=q and L=Hox complexes at 1.38 V vs. SCE and 1.42 V vs. SCE respectively. The osmium(III) species, viz. [OsIII(PPh3)2(N-N)Br2]+ and [OsIII(PPh3)2(phen)(L)]2+, have been generated both chemically and electrochemically and characterized in solution by electronic spectroscopy and cyclic voltammetry.  相似文献   

9.
Summary The RuIII complex [RuCl2(acac)(acacH)] (acacH = acetylacetone) was isolated in high yield by reacting RuCl3 with acacH. The compound was used as a convenient starting material for the synthesis of a variety of RuIII complexes, viz. [RuCl2(acac)L2] (L = PPh3, AsPh3, py, MeCN, Me2SO, o-phenylenediamine; L2 = phen or bipy) and M2[RuCl4(acac)] (M = Me4N, Rb or Cs). The compounds were characterized by physicochemical and spectroscopic methods.  相似文献   

10.
Three unsymmetrical tetradentate Schiff base ligands, H2salipn, H2salipn-Br4 and H2salipn-Cl2, have been synthesized from the typical condensation reactions of treating 1,2-diaminopropane with salicylaldehyde, 3,5-dibromosalicylaldehyde and 5-chlorosalicylaldehyde, respectively. Treatment of [RuCl2(PPh3)3] with one equivalent of H2salipn or H2salipn-Br4 in the presence of triethylamine in tetrahydrofuran (THF) afforded the corresponding ruthenium(III) complexes [RuIIICl(PPh3)(salipn)] (1) and [RuIIICl(PPh3)(salipn-Br4)] (2). Interaction of [RuHCl(CO)(PPh3)3] with one equivalent of H2salipn-Cl2 or H2salipn-Br4 under the same conditions led to isolation of ruthenium(II) complexes [RuII(CO)(PPh3)(salalipn-Cl2)] (3) and [RuII(CO)(PPh3)(salalipn-Br4)] (4), respectively, in which one of the imine bonds was nucleophilically attacked by hydride to result in the formation of a mixed imine-amine ligand. The molecular structures of 1?1.5CH2Cl2, 2, 3?0.5CH2Cl2 and 4 have been determined by single-crystal X-ray crystallography. The electrochemical properties of 14 were also investigated. Their cyclic voltammograms displayed quasi-reversible Ru(IV)/Ru(III) and Ru(III)/Ru(II) couples with Eo ranging from 0.67 to 1.05 V and 0.74 to 0.80 V vs. Ag/AgCl (0.1 M), respectively.  相似文献   

11.
A series of hexacoordinated RuIII–PPh3 complexes of general formula [RuCl(PPh3)L] (L = tetradentate Schiff bases derived from the condensation of 2-furaldehyde or thiophene-2-carboxyaldehyde with alkyl and aryl diamines have been synthesized. The complexes were characterized by elemental analyses, spectroscopic and cyclic voltammetric studies. All of the complexes were paramagnetic. Coordination of the Schiff base appears to occur through the two nitrogen and two heterocyclic oxygen/sulphur atoms.  相似文献   

12.
A series of octahedral RuII/RuIII complexes of the type [Ru(Y)(CO)(BAX)(PPh3)2] and [RuCl2(BAX)(PPh3)2] (Y = H or Cl; BAX = benzaldehydeacetylhydrazone anion; X = H, Me, OMe, OH, Cl or NO2) have been prepared and characterised by spectral, magnetic and cyclic voltammetric studies. The RuII complexes are low spin diamagnetic (S = 0) whereas the RuIII complexes are low spin and paramagnetic (S = 1/2). These RuII and RuIII complexes absorb in the visible region respectively at ca. 16,000 and 28,000 cm–1 which bands are assigned to the MLCT. The correlation of the max values of the RuIII complexes with the + Hammett parameter, is linear, indicating the profound effect of substituents on the electron density of the central metal. I.r. spectral data reveals that the hydrazone is chelated to ruthenium through the hydrazinic nitrogen and the deprotonated enolic oxygen. The rhombic nature of the e.s.r. spectra of the RuIII complexes indicates an asymmetry in the electronic environment around the Ru atom. RuII complexes in CH2Cl2 show an irreversible RuII/III redox couple at ca. 0.9–0.5 V, while the RuIII complexes show two reversible redox couples in the –0.1–0.1 and 0.8–0.6 V range, indicating that the higher oxidation state of ruthenium is stabilised by hydrazones.  相似文献   

13.
Reaction of 2-(phenylazo)pyridine (pap) with [Ru(PPh3)3X2] (X = Cl, Br) in dichloromethane solution affords [Ru(PPh3)2(pap)X2]. These diamagnetic complexes exhibit a weakdd transition and two intense MLCT transitions in the visible region. In dichloromethane solution they display a one-electron reduction of pap near − 0.90 V vs SCE and a reversible ruthenium(II)-ruthenium(III) oxidation near 0.70 V vs SCE. The [RuIII(PPh3)2(pap)Cl2]+ complex cation, generated by coulometric oxidation of [Ru(PPh3)2(pap)Cl2], shows two intense LMCT transitions in the visible region. It oxidizes N,N-dimethylaniline and [RuII(bpy)2Cl2] (bpy = 2,2′-bipyridine) to produce N,N,N′,N′-tetramethylbenzidine and [RuIII(bpy)2Cl2]+ respectively. Reaction of [Ru(PPh3)2(pap)X2] with Ag+ in ethanol produces [Ru(PPh3)2(pap)(EtOH)2]2+ which upon further reaction with L (L = pap, bpy, acetylacetonate ion(acac) and oxalate ion (ox2−)) gives complexes of type [Ru(PPh3)2(pap)(L)]n+ (n = 0, 1, 2). All these diamagnetic complexes show a weakdd transition and several intense MLCT transitions in the visible region. The ruthenium(II)-ruthenium(III) oxidation potential decreases in the order (of L): pap > bpy > acac > ox2−. Reductions of the coordinated pap and bpy are also observed.  相似文献   

14.
Reactions of ruthenium(II) complexes [RuHX(CO)(EPh3)2(B)] (X = H or Cl; B = EPh3, pyridine (py) or piperidine (pip); E = P or As) with bidentate Schiff base ligands derived by condensingo- hydroxyacetophenone with aniline,o- orp-methylaniline have been carried out. The products were characterized by analytical, IR, electronic and1H-NMR spectral studies and are formulated as [Ru(X)(CO) (L)(EPh3)(B)] (L = Schiff base anion; X = H or Cl; B = EPh3, py or pip; E = P or As). An octahedral structure has been tentatively proposed for the new complexes. The new complexes were tested for their catalytic activities in the oxidation of benzyl alcohol to benzaldehyde.  相似文献   

15.
Hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(PPh3)(Z)(L)] [Z = PPh3, pyridine (py) or piperidine (pip); L = anion of the Schiff base] have been prepared by reacting [RuHCl(CO)(PPh3)2(Z)] with tridentate Schiff bases derived by condensing anthranilic acid with acetylacetone, salicylaldehyde, o-vanillin and o-hydroxyacetophenone. The complexes were characterised by analytical and spectral (i.r., electronic, 1H- and 31P-n.m.r.) data, and were found to be effective catalysts for oxidising primary alcohols to aldehydes in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The Schiff bases and their ruthenium(II) complexes show growth inhibitory activity against pathogenic fungi Aspergillus flavus, Fusarium oxysporium and Rhizoctonia solani.  相似文献   

16.
The reaction of Ru3(CO)10(dotpm) ( 1 ) [dotpm = (bis(di‐ortho‐tolylphosphanyl)methane)] and one equivalent of L [L = PPh3, P(C6H4Cl‐p)3 and PPh2(C6H4Br‐p)] in refluxing n‐hexane afforded a series of derivatives [Ru3(CO)9(dotpm)L] ( 2 – 4 ), respectively, in ca. 67–70 % yield. Complexes 2 – 4 were characterized by elemental analysis (CHN), IR, 1H NMR, 13C{1H} NMR and 31P{1H} NMR spectroscopy. The molecular structures of 2 , 3 , and 4 were established by single‐crystal X‐ray diffraction. The bidentate dotpm and monodentate phosphine ligands occupy equatorial positions with respect to the Ru triangle. The effect of substitution resulted in significant differences in the Ru–Ru and Ru–P bond lengths.  相似文献   

17.
Herein we report the synthesis and characterization of trans-[RuIICl2(PPh3)3] with potentially tridentate Schiff bases derived from 5,6-diamino-1,3-dimethyl uracil (H2ddd) and two 2-substituted aromatic aldehydes. In the diamagnetic ruthenium(II) complexes, trans-[RuCl(PPh3)2(Htdp)] (1) {H2tdp = 5-((thiophen-3-yl)methyleneamino)-6-amino-1,3-dimethyluracil} and trans-[RuCl(PPh3)2(Hsdp)] (2) {H2sdp = 5-(2-(methylthio)benzylideneamino)-6-amino-1,3-dimethyluracil}, the Schiff base ligands (i.e. Htdp and Hsdp) act as mono-anionic tridentate chelators. Upon reacting 5-(2-hydroxybenzylideneamino)-6-amino-1,3-dimethyluracil (H3hdp) with the metal precursor, the paramagnetic complex, trans-[RuIVCl2(ddd)(PPh3)2] (3), was isolated, in which the bidentate dianionic ddd co-ligand was formed by hydrolysis. The metal complexes were fully characterized via multinuclear NMR-, IR-, and UV–Vis spectroscopy, single crystal XRD analysis and conductivity measurements. The redox properties were probed via cyclic voltammetry with all complexes exhibiting comparable electrochemical behavior with half-wave potentials (E½) at 0.70 V (for 1), 0.725 V (for 2), and 0.68 V (for 3) versus Ag|AgCl, respectively. The presence of the paramagnetic metal center for 3 was confirmed by ESR spectroscopy.  相似文献   

18.
Stable ruthenium(II) complexes of Schiff bases have been prepared by reacting [RuHCl(CO)(PPh3)2(B)] (B = PPh3, pyridine or piperidine) with bis(o-vanillin)ethylenediimine (valen), bis(o-vanillin)propylene-diimine (valpn), bis(o-vanillin)tetramethylenediimine (valtn), bis(o-vanillin)o-phenylenediimine (valphn), bis(salicylaldehyde)tetramethylenediimine (saltn) and bis(salicylaldehyde)o-phenylenediimine (salphn). These complexes have been characterised by elemental analyses, i.r., electronic, 1H- and 31P{1H}-n.m.r. spectral studies. In all the above reactions, the Schiff bases replace two molecules of Ph3P, a hydride and a halide ion from the starting complexes, indicating that the Ru–N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru–P bond to Ph3P. The new complexes of the general formula [Ru(CO)(B)(L)] (B = PPh3, py or pip; L = tetradentate Schiff bases) have been assigned an octahedral structure. Some of the Schiff bases and the new complexes have been tested against the pathogenic fungus Fusarium sp.  相似文献   

19.
The complex [MnIV(napbh)2] (napbhH2 = N-(2-hydroxynaphthalen-1-yl)methylenebenzoylhydrazide) reacts with activated ruthenium(III) chloride in methanol in 1 : 1.2 molar ratio under reflux, giving heterobimetallic complexes, [MnIV(napbh)2RuIIICl3(H2O)] · [RuIII(napbhH)Cl2(H2O)] reacts with Mn(OAc)2·4H2O in methanol in 1 : 1.2 molar ratio under reflux to give [RuIII(napbhH)Cl2(H2O)MnII(OAc)2]. Replacement of aquo in these heterobimetallic complexes has been observed when the reactions are carried out in the presence of pyridine (py), 3-picoline (3-pic), or 4-picoline (4-pic). The molar conductances for these complexes in DMF indicates 1 : 1 electrolytes. Magnetic moment values suggest that these heterobimetallic complexes contain MnIV and RuIII or RuIII and MnII in the same structural unit. Electronic spectral studies suggest six coordinate metal ions. IR spectra reveal that the napbhH2 ligand coordinates in its enol form to MnIV and bridges to RuIII and in the keto form to RuIII and bridging to MnII.  相似文献   

20.
Abstract

The triply chloro-bridged binuclear complex [Ru2Cl5(CO)(PPh3)3]·CH2Cl2, (PPh3 = triphenylphosphine), Mr = 1279.23, prepared from the precursor compound [RuCl3(PPh3)2DMA]·DMA (DMA = N,N′-dimethylacetamide) and crystallizes in the monoclinic space group P21/c. The structure was solved from 6994 independent reflections for which I > 3σ(I) by Patterson and difference Fourier techniques and refined to a final R = 0.042. The complex is formed by two Ru atoms bridged through three chloride anions. One Ru atom is further coordinated to two non-bridging Cl atoms and a triphenylphosphine ligand, whereas the other is bonded to two PPh3 ligands and a carbon monoxide molecule. The presence of RuIII was confirmed by EPR data. The absence of an intervalence charge-transfer transition (IT) in the near-infrared spectrum suggests that the binuclear complex is of a localized valence type. The IR spectrum shows a νCO band at 1964cm? and νRu-Cl bands at 328, 280 cm?1, corresponding to chlorides at terminal positions and 250, 225 cm?1 for the bridged ones. Two redox processes, RuII/RuII (E1/2 = -0.29 V) ← RuII/RuIII ← (E1/2 = 1.19 V) RuIII/RuIII, were observed by cyclic voltammetry.  相似文献   

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